<select id="tgt_name" class="form-control" name="tgt">
    <option value="" selected="selected">选择项目参数</option>
    {% for i in rst_data %}
        <option value="{{ i }}">{{ i }}</option>
    {% endfor %}
</select>

<script>
    $('#tgt_name').change(function() {
       $("#update_log").show();
        return false;
   });
</script>
